Hessian Test Failures

[MasonProtter]

https://github.com/YingboMa/ForwardDiff2.jl/blob/master/test/api.jl#L56

using Test
using ForwardDiff2: D, DI, ForwardDiff2
using StaticArrays
using LinearAlgebra

julia> let
               dh1 = D(DI(x->x[1]^x[2] + x[3]^3 + x[3]*x[2]*x[1]))
               dh2 = D(D(x->x[1]^x[2] + x[3]^3 + x[3]*x[2]*x[1]))
               for dh in (dh1, dh2,)
                   @test dh(@SVector[1,2,3]) * I == @SMatrix [2 4 2; 4 0 1; 2 1 18.0]
                   # @test dh([1,2,3]) * I == [2 4 2; 4 0 1; 2 1 18.0]
                   # @test dh([1,2,3]) * @SVector([1, 2, 3]) == @SVector [16, 7, 58.0]
               end
           end
Error During Test at REPL[9]:5
  Test threw exception
  Expression: dh(#= REPL[9]:5 =# @SVector([1, 2, 3])) * I == #= REPL[9]:5 =# @SMatrix([2 4 2; 4 0 1; 2 1 18.0])
  StackOverflowError:
  Stacktrace:
   [1] log(::ForwardDiff2.Dual{ForwardDiff2.Tag{Nothing},Float64,SArray{Tuple{3},Int64,1,3}}) at ./special/log.jl:395 (repeats 79984 times)
  
ERROR: There was an error during testing

(@v1.4) pkg> st ForwardDiff2 Cassette
Status `~/.julia/environments/v1.4/Project.toml`
  [7057c7e9] Cassette v0.3.1 [`~/.julia/dev/Cassette`]
  [994df76e] ForwardDiff2 v0.2.2 [`~/.julia/dev/ForwardDiff2`]

julia> versioninfo()
Julia Version 1.4.0
Commit b8e9a9ecc6* (2020-03-21 16:36 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: AMD Ryzen 5 2600 Six-Core Processor
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-8.0.1 (ORCJIT, znver1)
Environment:
  JULIA_NUM_THREADS = 6